Background Biological agents are used to treat rheumatic diseases. Patients are initially treated at the recommended dose according to the results of clinical trials but there is no current consensus on what attitude to take following remission. The practice of dose optimisation (DO) is spreading among professionals, resulting in an effective strategy.

Purpose To evaluate the impact of etanercept DO in patients with chronic rheumatic diseases, in a real world setting.

Material and methods Descriptive, cross-sectional study between January and July 2015. Data were collected by reviewing patient’s clinical records. DO was defined as a treatment regimen with a reduced amount of drug than recommended in the product labelling, either by using lower doses or by spacing the intervals of administration. Measured parameters were: Disease Activity Score of 28 joints (DAS28) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) before and after DO, therapeutic regimens and reasons for withdrawal.

Results 193 patients received treatment with etanercept. Optimisation was started in 53 (27.5%) patients by spacing the dose interval: rheumatoid arthritis (43%), psoriatic arthritis (32%) and ankylosing spondylitis (25%).

55% were women, and mean age was 49 years.

At the standard dose, average values for DAS28 and BASDAI were 2.1 and 2.1, respectively, versus 2.0 and 2.6 at DO. In 11 patients, data were not available.

30% of patients showed a reduction in clinical parameters considered (54% of DAS28 and BASDAI 10%), 22% presented no differences (8% DAS28 and BASDAI 40%) and 48% showed an increase (46% of DAS28 and BASDAI 50%) although they were not clinically relevant.

The most common therapeutic regimens used were: 25 mg/week (70%), 25 mg/2 weeks (11%) and 25 mg/10 days (7%).

3 (5.6%) returned to the recommended label dose, having good disease control to date.

Conclusion In our clinical practice, 27.5% of chronic rheumatic patients received DO of etanercept, showing a risk of relapse in 5.6% of cases but reinstatement of the recommended label dose seemed to reinstate disease control. Optimisation of biological treatment in rheumatic diseases could be effective resulting in less exposure. However, well designed studies are needed to establish the best optimisation strategy.

No conflict of interest.